The aerobic oxidation of trans-1,2-cyclohexanediol in the synthesis of adipic acid was studied. Two classes of catalysts are compared, 1) alumina-supported Ru(OH)3, and 2) Keggin type P/Mo/V polyoxometalates. These two classes are representative examples because they are active in alcohol oxidation under quite different reaction conditions. In the former case, basic conditions are needed in order to activate the substrate, whereas with polyoxometalates, acidic conditions are used. Their catalytic behavior showed remarkable differences; in basic conditions, the reaction network was very complex, and several side reactions led to a number of by-products, with a low selectivity to adipic acid in the end. The supported Ru(OH)3 catalyst was very efficient in 1,2-cyclohexanediol oxidative dehydrogenation to 1,2-cyclohexanedione, but several undesired reactions occurred starting from this key intermediate under basic conditions: rearrangement into 6-hydroxycaprolactone and 1-hydroxycyclopentanecarboxylic acid, and formation of the product of aldol condensation. The former compound was also an intermediate for adipic acid formation, but this reaction gave only a minor contribution to the reactant conversion. Polyoxometalates were extremely selective in 1,2-cyclohexanediol conversion into adipic acid, but under acidic conditions the product reacted with the unconverted reactant to yield the corresponding ester.

Oxidation of 1,2-Cyclohexanediol to Adipic Acid with Oxygen: A Study Into Selectivity-Affecting Parameters

CERRATO, Giuseppina;MANZOLI, Maela;
2013

Abstract

The aerobic oxidation of trans-1,2-cyclohexanediol in the synthesis of adipic acid was studied. Two classes of catalysts are compared, 1) alumina-supported Ru(OH)3, and 2) Keggin type P/Mo/V polyoxometalates. These two classes are representative examples because they are active in alcohol oxidation under quite different reaction conditions. In the former case, basic conditions are needed in order to activate the substrate, whereas with polyoxometalates, acidic conditions are used. Their catalytic behavior showed remarkable differences; in basic conditions, the reaction network was very complex, and several side reactions led to a number of by-products, with a low selectivity to adipic acid in the end. The supported Ru(OH)3 catalyst was very efficient in 1,2-cyclohexanediol oxidative dehydrogenation to 1,2-cyclohexanedione, but several undesired reactions occurred starting from this key intermediate under basic conditions: rearrangement into 6-hydroxycaprolactone and 1-hydroxycyclopentanecarboxylic acid, and formation of the product of aldol condensation. The former compound was also an intermediate for adipic acid formation, but this reaction gave only a minor contribution to the reactant conversion. Polyoxometalates were extremely selective in 1,2-cyclohexanediol conversion into adipic acid, but under acidic conditions the product reacted with the unconverted reactant to yield the corresponding ester.
CHEMCATCHEM
5
1998
2008
http://onlinelibrary.wiley.com/doi/10.1002/cctc.201200825/abstract;jsessionid=B2F1F76B68D8B3F324A33575B57D17FE.d01t03?systemMessage=Wiley+Online+Library+will+be+disrupted+on+11+May+from+10%3A00-12%3A00+BST+%2805%3A00-07%3A00+EDT%29+for+essential+maintenance
adipic acid; polyoxometalates; reaction mechanisms; ruthenium
Elena Rozhko; Katerina Raabova; Francesco Macchia; Andrea Malmusi; Paolo Righi; Pasquale Accorinti; Stefano Alini; Pierpaolo Babini; Giuseppina Cerrato; Maela Manzoli; Fabrizio Cavani
File in questo prodotto:
File Dimensione Formato  
RuChemCatChem2013.pdf

non disponibili

Tipo di file: PDF EDITORIALE
Dimensione 766.42 kB
Formato Adobe PDF
766.42 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
manuscript_CCC_4aperto.pdf

accesso aperto

Descrizione: Articolo principale
Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 623.11 kB
Formato Adobe PDF
623.11 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2318/132956
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 27
  • ???jsp.display-item.citation.isi??? 25
social impact